The invention relates to a method for determining a power consumption in an electrical installation, in which a group of several individual distribution branches connected in parallel is connected to an alternating current power supply. The method in question is of the type comprising the action of performing in time and of recording measurements of the overall supply voltage of the group of several branches, and measurements of the intensity and phase shift values of the overall supply current of this group.
The invention also relates to an alternating current electrical installation of the type comprising a group of several individual distribution branches connected in parallel, and a monitoring system designed to perform in time and to record measurements of an overall supply voltage of the group of several branches, and measurements of the intensity and phase shift values of the overall supply current of this group.